Field of the Invention
This invention relates to a convection oven having multiple airflow patterns within a cooking chamber during the baking cycle. The convection oven has at least one blower wheel rotatable at different speeds and/or in different directions for creating multiple airflow patterns within the cooking chamber during a baking cycle. Alternatively, at least one mechanically actuated adjustable airflow control surface creates multiple airflow patterns within the cooking chamber during a baking cycle.
Description of Related Art
Conventional commercial convection ovens have one or more fans which circulate air within an oven cavity. The airflow within the oven cavity is highly turbulent but characterized by a circulation pattern evident in the oven""s cooking performance. A distinct and often undesirable pattern is seen on the cooked food product. In areas of the oven cavity where the airflow is too low, the food product will be raw or uncooked. Conversely, in areas where the airflow is too high, the food product will be burned or overcooked. In such situations, it is desirable to tune the convection oven so that a uniform airflow is obtained.
Many conventional commercial convection ovens are tuned by attempting to produce a single flow pattern having a uniform flow and temperature distribution within the oven cavity. However, accurately tuning conventional convection ovens is difficult, and often a trial and error process.
It is apparent that there is a need for an easy and effective method for tuning the baking performance of a convection oven wherein multiple airflow patterns are created within the cooking chamber during a baking cycle.
It is an object of this invention to provide a convection oven having an easy and effective method for providing multiple airflow patterns within the cooking chamber during the baking cycle.
It is another object of this invention to provide a convection oven having at least one blower wheel rotatable at different speeds and/or in different directions for creating multiple airflow patterns within the cooking chamber during a baking cycle.
It is another object of this invention to provide a convection oven having at least one adjustable airflow control surface for creating multiple airflow patterns within the cooking chamber during a baking cycle.
The above objects and other objects of this invention are accomplished by a convection oven having a cooking chamber with dimensions to accommodate any type, quantity and/or size of food product. An outer enclosure is in communication with the cooking chamber. In one preferred embodiment, at least one reversible blower wheel, preferably at least two reversible blower wheels, are mounted within the outer enclosure.
The reversible blower wheels rotate in the same direction with respect to each other or in different or opposite directions with respect to each other, producing at least four separate airflow states to create different airflow patterns within the cooking chamber. Additional airflow patterns are created by varying the speed at which the reversible blower wheels rotate with respect to each other.
In another preferred embodiment of this invention, at least one adjustable airflow control surface is mounted within the cooking chamber. The adjustable airflow control surface has, for example a baffle or a fin which is adjustable between a plurality of positions to change the geometry of the cooking chamber. An actuator adjusts the adjustable airflow control surface between a plurality of positions during the baking cycle. As a result, additional airflow states are produced which create multiple airflow patterns within the cooking chamber. The airflow states can be switched in a predetermined cycle or a random cycle. A uniform baking performance is obtained by averaging the multiple airflow patterns created by periodically switching between the airflow states during the baking cycle. The baking performance of the average state is better than the baking performance of any individual airflow state.
In one preferred embodiment of this invention, a removable inlet baffle is positioned between the cooking chamber and the outer enclosure. Preferably, the inlet baffle has an air return in communication with each reversible blower wheel to allow communication between the cooking chamber and the outer enclosure. The inlet baffle may have a plurality of apertures to allow communication between the cooking chamber and the outer enclosure.
The convection oven has a gas combustion system mounted with respect to the outer enclosure which produces or generates combustion products. The combustion products generated by the gas combustion system move into a heat exchange element. The heat exchange element is mounted within the outer enclosure and with respect to the reversible blower wheels.
In one preferred embodiment according to this invention, separate airflow states are produced by varying the speeds at which the reversible blower wheels rotate with respect to each other and/or changing the direction in which the reversible blower wheels rotate. By varying the respective speed and/or rotational direction of the reversible blower wheels to produce separate airflow states, multiple airflow patterns are created within the cooking chamber. These airflow patterns can be switched or changed periodically during the baking cycle to improve the baking performance of the convection oven.
In another preferred embodiment according to this invention, the adjustable airflow control surface produces multiple airflow patterns within the cooking chamber by adjusting the adjustable airflow control surface with an actuator to produce different airflow states. Multiple airflow patterns are created during the baking cycle of the convection oven by adjusting the adjustable airflow control surface, improving the baking performance of the convection oven.